1. Technical Field
This disclosure relates to an apparatus and method for the biopsy of tissue specimens and, more particularly, to a single insertion, multiple sample percutaneous biopsy apparatus and method.
2. Background of Related Art
It is often necessary to sample tissue in order to diagnose and treat patients suspected of having cancerous tumors, pre-malignant conditions and other diseases or disorders. Typically, in the case of suspected cancerous tissue, when the physician establishes by means of procedures such as palpation, x-ray or ultrasound imaging that suspicious conditions exist, a biopsy is performed to determine whether the cells are cancerous. Biopsy may be done by an open or percutaneous technique. Open biopsy removes the entire mass (excisional biopsy) or a part of the mass (incisional biopsy). Percutaneous biopsy on the other hand is usually done with a needle-like instrument and may be either a fine needle aspiration (FNA) or a core biopsy. In FNA biopsy, individual cells or clusters of cells are obtained for cytologic examination and may be prepared such as in a Papanicolaou smear. In core biopsy, as the term suggests, a core or fragment tissue is obtained for histologic examination which may be done via frozen section or paraffin section. In more recent developments percutaneous techniques have been used to remove the entire mass during the initial procedure.
The type of biopsy utilized depends in large part on the circumstances present with respect to the patient and no single procedure is ideal for all cases. Core biopsy, however, is extremely useful in a number of conditions and is being used more frequently.
Intact tissue from the organ or lesion is preferred by medical personnel in order to arrive at a definitive diagnosis regarding the patient""s condition. In most cases only part of the organ or lesion need be sampled. The portions of tissue extracted must be indicative of the organ or lesion as a whole. In the past, to obtain adequate tissue from organs or lesions within the body, surgery was performed so as to reliably locate, identify and remove the tissue. With present technology, medical imaging equipment such as stereotactic x-ray, fluoroscopy, computer tomography, ultrasound, nuclear medicine and magnetic resonance imaging, may be used. These technologies make it possible to identify small abnormalities even deep within the body. However, definitive tissue characterization still requires obtaining adequate tissue samples to characterize the histology of the organ or lesion.
Mammography can identify non-palpable (not perceptible by touch) breast abnormalities earlier than they can be diagnosed by physical examination. Most non-palpable breast abnormalities are benign but some are malignant. When breast cancer is diagnosed before it becomes palpable, breast cancer mortality can be reduced. It is still difficult to determine if pre-palpable breast abnormalities are malignant, as some benign lesions have mammographic features which mimic malignant lesions and some malignant lesions have mammographic features which mimic benign lesions. Thus, mammography has its limitations. To reach a definitive diagnosis, tissue from within the breast must be removed and examined under a microscope.
The introduction of stereotactic guided percutaneous breast biopsies offered alternatives to open surgical breast biopsy. With time, these guidance systems have become more accurate and easier to use. Biopsy guns were introduced for use in conjunction with these guidance systems. Accurate placement of the biopsy guns was important to obtain useful biopsy information because only one small core could be obtained per insertion at any one location. To sample the lesion thoroughly, many separate insertions of the instrument had to be made.
Biopsy procedures may benefit from larger tissue samples being taken, for example, tissue samples as large as 10 mm across. Many of the prior art devices required multiple punctures into the breast or organ in order to obtain the necessary samples. This practice is both tedious and time consuming.
One further solution to obtain a larger tissue sample is to utilize a device capable of taking multiple tissue samples with a single insertion of an instrument. An example of such a device is found in U.S. Pat. No. 5,195,533 to Chin et al. which describes a technique for extracting multiple samples with a single insertion of the biopsy device. Generally, such biopsy instruments extract a sample of tissue from a tissue mass by either drawing a tissue sample into a hollow needle via an external vacuum source or by severing and containing a tissue sample within a notch formed on a stylet. Typical of such devices utilizing an external vacuum source are U.S. Pat. No. 5,246,011 issued to Cailouette and U.S. Pat. No. 5,183,052 issued to Terwiliger. Such devices generally contemplate advancing a hollow needle into a tissue mass and applying a vacuum force to draw a sample into the needle and hold the same therein while the tissue is extracted.
When extracting multiple samples with a single insertion of the biopsy device using suction to either draw in tissue or remove the tissue from the body, it is important that the vacuum path remain unclogged. If the vacuum path clogs, the sample removal will become difficult or impossible. This may necessitate multiple insertions of the device or reduce the sample mass per extraction.
Therefore, a continuing need exists for percutaneous biopsy apparatus and methods which can reliably extract adequate biopsy sample(s) with a single insertion of the biopsy instrument.
The present disclosure describes an apparatus and method for the biopsy of tissue specimens and, more particularly, to a single insertion multiple sample percutaneous biopsy apparatus and method. A tip at a distal end of a vacuum support tube is introduced into a tissue mass. The vacuum support tube is retracted exposing a basket tube bounded by a front washer and a rear washer mounted thereabout forming a tissue basket. The basket tube is supported internally by a thrust tube which provides structure to the apparatus to allow it to penetrate tissue. The thrust tube and the basket tube are in fluid communication and are provided with suction to draw tissue inward. The tissue is then severed by rotating and advancing a knife edge at the distal end of the vacuum support tube. The tissue basket is withdrawn and the tissue sample is removed by rotating the vacuum support tube. The tissue sample is sliced longitudinally, and a stripper scrapes the tissue sample from an opening in the vacuum support tube.
The surgical biopsy apparatus disclosed includes a base portion having a proximal and a distal end. Desirably, the base portion further comprises a nose support, a center support and a back support.
The apparatus further includes a first elongated tubular member having a proximal and a distal end and is removably supported in the base portion and further defines a fluid passageway. The proximal end of the first elongated member is supported at the proximal end of the base portion. The first elongated tubular member includes a tip portion disposed at its distal end and adapted to penetrate tissue and a plurality of openings formed adjacent its distal end and in fluid communication with the fluid passageway. Preferably, the distal end of the first elongated tubular member is supported at the back support of the base portion. Most preferably, the tip has a tapered closed distal end and a stepped proximal end configured to cooperatively engage the distal end of the first elongated tubular member.
A suction junction is fixedly supported at the proximal end of the base portion and removably mounted to the proximal end of the first elongated tubular member and in fluid communication therewith.
The apparatus also includes a second elongated tubular member having a proximal and a distal end and is reciprocatingly disposed coaxially about the first elongated tubular member and is movable from a retracted position to an extended position. The distal end of the second elongated tubular member is disposed laterally adjacent to the plurality of openings of the first elongated member and supported at the proximal end of the base portion. The second elongated tubular member defines a tissue receiving portion disposed adjacent to its distal end and further defines a plurality of openings in fluid communication with the plurality of openings of the first elongated member. Preferably, the second elongated tubular member is supported at the back support of the base portion.
A third elongated tubular member is included having a proximal and an open distal end and is slidably mounted to the base portion and rotatably and reciprocatingly disposed coaxially about the first and second elongated tubular members. The third elongated tubular member includes a cutting edge formed at the open distal end and a lateral tissue discharge port. The third elongated tubular member is movable from an extended position wherein the cutting edge is disposed adjacent the tip portion of the first elongated tubular member and a retracted position wherein the lateral tissue discharge port is disposed laterally adjacent the tissue receiving portion of the second elongated tubular member. A vacuum port assembly is fixedly mounted to the proximal end of the second elongated tubular member and in fluid communication therewith. Preferably, a control member is mounted to its proximal end. Most preferably, the control member has a circular configuration and defines a knurled outer peripheral surface.
In a preferred embodiment, the apparatus includes a latch plate assembly attached to the base portion between the center and back supports. The latch plate assembly includes a first latch having a cantilevered portion and a camming surface resiliently biased against the control member. The cantilevered portion releasably locks the third elongated tubular member at its distalmost position.
In another preferred embodiment, the latch plate assembly further comprises a second latch having a cantilevered portion and a camming surface resiliently biased against the vacuum port assembly. The cantilevered portion releasably locks the vacuum port assembly at its distalmost position.
In yet another preferred embodiment, the second elongated tubular member defines a fluid passageway in fluid communication with the vacuum port assembly. Preferably, the second elongated tubular member further includes a front washer and a rear washer that define the tissue receiving portion therebetween. The rear washer further defines a plurality of transverse openings spaced radially thereabout in fluid communication with the fluid passageway of the second elongated tubular member.
In one particular embodiment, a cutting element is longitudinally attached to an exterior surface of the first elongated tubular member and positioned to sever a tissue sample. Preferably, the second elongated tubular member defines a slot for receiving the cutting element.
In another embodiment, the apparatus comprises a tissue stripping member mounted to the base portion and disposed between the nose support and the center support. The tissue stripping member includes a flexible extended portion configured and dimensioned to enter the tissue discharge port of the third elongated tubular member upon alignment of the tissue discharge port with the tissue receiving portion of the second elongated tubular member. Preferably, the tissue stripping member includes a friction reducing coating formed thereon to reduce friction with body tissue coming in contact with the tissue stripping member.
A method of performing a surgical biopsy is disclosed comprising the steps of: inserting a biopsy apparatus into the tissue of a patient, the biopsy apparatus including: a first elongated tubular member defining a fluid passageway and having a tip portion at the distal end for penetrating tissue and further defining a plurality of openings formed adjacent the distal end and in fluid communication therewith, a second elongated tubular member defining a tissue receiving portion and a plurality of openings in fluid communication with the plurality of openings of the first elongated tubular member, and a third elongated tubular member having a cutting edge formed at an open distal end and defining a lateral tissue discharge port, extending the second elongated tubular member to align the plurality of openings of the first elongated tubular member and the plurality of openings of the second elongated tubular member, retracting the third elongated tubular member to expose the tissue receiving portion of the second elongated tubular member, applying suction to the fluid passageway of the first elongated tubular member in fluid communication with the plurality of openings of the first elongated tubular member and thereby in fluid communication with the plurality of openings of the second elongated tubular member to pull tissue into the tissue receiving portion, severing tissue disposed within the tissue receiving portion by extending the third elongated tubular member to adjacent the closed distal tapered end portion of the first elongated tubular member such that a cutting surface formed on the open distal end of the third elongated tubular member rotates as it passes over the tissue receiving portion, and removing the severed tissue sample from the tissue sampling site by applying suction to a fluid passageway defined in the second elongated tubular member in fluid communication with a plurality of openings defined within a rear washer of the second elongated tubular member, retracting the second elongated tubular member and thereby pulling the severed tissue sample until the tissue receiving portion is aligned with the lateral discharge port of the third elongated tubular member wherein a tissue stripping plate urges the tissue sample out of the tissue receiving portion.